1. Field of the Invention
The present invention relates generally to testing networking systems. More particularly, embodiments of the invention relate to systems and methods for altering latency to test data transmission systems and components.
2. Background Technology
Communication networks—including wide area networks (“WANs”), local area networks (“LANs”), metropolitan area networks (“MANs”), and storage area networks (“SANs”)—allow increased productivity and use of distributed computers. Moreover, network applications such as electronic mail, voice and data transfer, host access, and shared and distributed databases are increasingly used as a means to increase user productivity using communications networks.
Many different physical configurations of networks presently exist. Examples include Gigabit Ethernet (“GE”), 10 GE, Fiber Distributed Data Interface (“FDDI”), Fibre Channel (“FC”), Serial Attached SCSI (SAS) and Serial ATA (SATA), Synchronous Optical Network (“SONET”) and InfiniBand networks. These networks, and others, typically conform to one of a variety of established standards, or protocols, which set forth rules that govern network access as well as communications between and among the network resources.
As communication networks have increased in size, speed and complexity however, they have become increasingly likely to develop a variety of problems that, in practice, have proven difficult to diagnose and resolve. Such problems are of particular concern in light of the continuing demand for high levels of network operational reliability and for increased network capacity.
The problems generally experienced in network communications can take a variety of forms and may occur as a result of a variety of different circumstances. Examples of circumstances, conditions and events that may give rise to network communication problems include the transmission of unnecessarily small frames of information, inefficient or incorrect routing of information, improper network configuration and superfluous network traffic, to name just a few. Such problems are aggravated by the fact that networks are continually changing and evolving due to growth, reconfiguration and introduction of new network topologies and protocols. Moreover, new network interconnection devices and software applications are constantly being introduced and implemented. Circumstances such as these highlight the need for effective, reliable, and flexible diagnostic mechanisms.
Consequently, as high speed data communications systems, processes and devices mature, many designs have increasingly focused on reliability and performance issues. Accordingly, a number of diagnostic devices (e.g., protocol analyzers, generators, bit error rate testers, jammers) and tests can be utilized to aid a network administrator in both identifying existing network conditions that are causing a network to deviate from expected performance and proactively identifying network conditions that may cause a network to deviate from expected performance in the future.
When adding new devices to an existing network or installing an entirely new network of devices, a network administrator may use many of these diagnostic devices to ensure the quality of the network. Unfortunately, the network administrator may wish to install these network devices miles away from each other—even tens, hundreds, or thousands of miles away from each other. To test these devices, a network administrator could travel from location to location to make modifications to the network. However, the network administrator would incur the associated travel expenses, which can be expensive. Also, the network administrator might waste hours or even days traveling, which the network administrator could have spent testing the network. In fact, even when the devices are a relatively short distance apart, a network administrator may wish to make several minor modifications to several network devices—making shorter distances equally burdensome.
Because network devices may be installed in different locations, some network administrators could choose to interconnect network devices locally for testing before installing them remotely. However, to properly test using the latency associated with the lengths of a particular type of communications medium (such as, optical fiber), these network administrators might attempt to purchase spools of the communications medium to interconnect the devices being tested. Unfortunately, the supply of spools can be limited, and, at times, unavailable in the amounts necessary for testing. Even when available, the spools can be too expensive for many network administrators.
Similarly, prior to a product release, manufacturers of network devices may wish to test the performance of their devices in various environments—including at distances of tens, hundreds, or thousands of miles. For example, network device manufacturers may want to test timeout conditions. However, as mentioned above, the supply of spools can be insufficient and can be expensive. Further, to test a network device's performance at various distances, the manufacturer might waste hours of time assembling the varied lengths of connection medium—increasing the testing costs and delaying the release of their products to the public.